What is Base64 encoding used for?

Base64 encoding converts binary data into ASCII text format, making it safe for transmission over text-based protocols like HTTP, email (MIME), JSON APIs, and URLs. Common uses include encoding images as data URIs, handling API authentication tokens, embedding files in HTML/CSS, and storing binary data in text-only systems like localStorage.

Is Base64 encryption?

No, Base64 is encoding, not encryption. Anyone can decode Base64 strings instantly—there's no key or password protection. Never use Base64 alone to protect sensitive data. It's designed for data transmission and compatibility, not security. For security, use proper encryption algorithms like AES with Base64 encoding afterward if needed for transport.

Why does Base64 make data larger?

Base64 encoding increases data size by approximately 33% because it represents 3 bytes of binary data using 4 ASCII characters. This trade-off ensures the data can be safely transmitted through text-only channels. For example, a 30KB image becomes ~40KB when Base64 encoded. Use compression before encoding for large files.

How does this tool handle special characters and emoji?

Our tool uses UTF-8 encoding to properly handle all Unicode characters including emoji (😀🌍), international characters (你好, مرحبا, Привет), and special symbols. We use encodeURIComponent/decodeURIComponent internally to ensure correct multi-byte character handling, unlike basic btoa/atob which can fail with non-ASCII characters.

What does 'Invalid Base64 string' error mean?

This error occurs when the input contains characters outside the Base64 alphabet (A-Z, a-z, 0-9, +, /, =), has incorrect padding, or is corrupted. Common causes: copying partial strings, including whitespace/newlines (remove them first), or trying to decode plain text. Valid Base64 strings only use 64 specific characters plus = for padding.

Can I use this for encoding files or images?

This tool is designed for text encoding/decoding. For files and images, you'll need to first convert them to text format (like reading as binary in JavaScript). However, you can decode Base64-encoded images (data URIs) to see the encoded text, or encode small text-based files. For large binary files, use specialized file encoding tools.

What is the difference between Base64 and Base64URL?

Standard Base64 uses + and / characters which are not URL-safe. Base64URL replaces + with - (minus) and / with _ (underscore), making it safe for URLs and filenames without percent-encoding. Our tool uses standard Base64. For Base64URL, manually replace +→-, /→_, and remove trailing = padding after encoding.

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Base64 Encoder/Decoder

Encode and decode Base64 strings with UTF-8 support. Perfect for encoding text, handling API tokens, embedding data URIs, and debugging web applications.

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How to Use Base64 Encoder/Decoder

What is Base64?

Base64 is an encoding scheme that converts binary data into ASCII text format using 64 printable characters (A-Z, a-z, 0-9, +, /). It's commonly used in web development, APIs, and data transmission.

How to Use This Tool

Encoding Text to Base64

Select Encode mode (default)
Type or paste your text in the Input Text area
Click Convert to encode
Your Base64 string appears in the Output panel
Click Copy Output to copy the encoded result

Decoding Base64 to Text

Click Decode mode
Paste your Base64 string in the Input Base64 area
Click Convert to decode
Your decoded text appears in the Output panel
Click Copy Output to copy the decoded result

Features

UTF-8 Safe: Properly handles emoji, international characters, and special symbols
Bidirectional: Switch between Encode and Decode modes instantly
Error Handling: Clear error messages for invalid Base64 strings
Quick Actions: Convert, Swap modes, Copy output, Clear all, or try Sample data
Real-time Status: Visual indicators show conversion status (Idle/Success/Error)

Common Use Cases

API Authentication: Encode credentials for Basic Auth headers
Data URIs: Embed images or files in HTML/CSS using Base64
URL-Safe Data: Encode text for transmission in URLs or query parameters
Email Attachments: Handle MIME-encoded email content
Debugging: Decode Base64 tokens, cookies, or configuration values
Web Storage: Store binary data in localStorage or cookies

Tips

Base64 encoding increases data size by approximately 33%
Always use UTF-8 encoding for text to avoid character corruption
Remove whitespace from Base64 strings before decoding
Base64 is encoding, not encryption—it doesn't provide security

Frequently Asked Questions

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